US1874446A - Ported cylinder construction - Google Patents

Description

Aug. 30, 1932. R. CHILTON 1,874,446

P ORTED CYLINDER CONSTRUCTION Filed March 26. 1931 INVENTOR. 201mm (271.17 TON Patented Aug. 30, 1932 Y UNITED STATES PATENT OFFICE ROLAND CHILTON, OF BIDGEWOOD, JERSEY, ASSIGNOR TO WRIGHT AERO NAUTICAL CORPORATION, A CORPORATION OF NEW YORK PORTED CYLINDER CONSTRUCTION Application filed March 26, 1931. Serial No. 525,494.

This invention relates to ported cylinders, such as are used in two-cycle internal combustion engines, wherein exhaust or inlet ports are uncovered by the piston during its travel. 7

A prime object of the invention is to achieve good cooling of the cylinder sleeve in the neighborhood of the ports, and particularly to improve the vconductive path for heat travel from the bars between adjacent ports to the cooling medium. In the embodiment illustrated, water cooling is indicated, but it will be understood that the invention is applicable to air or other cooling means.

A further object of the invention is to provide good cooling for the port zone in a liner type cylinder, wherein a sleeve is inserted in a jacketed casting, which may then be of aluminum or other light alloy, whereby substantial weight saving is effected.v In the prior art, sleeves of uniformthickness have been used whereby the bars are relatively slender, giving veryslight endwise conductivity'for abstraction of heat. Such slender bars are also subject to distortion whereby they tend to move out of contact with the cylinder casting, the space thus formed usually becoming filled with carbon, which is a poor heat conductor. In the present invention, on the contrary, the sleeve is fabricated with an integral collar of relatively great radial extension thru which the ports are pierced. The cylinder body is formed in two pieces, between which the port belt of the sleeve is firmly pinched by accurately machined faces, giving intimate thermal contact. Due to the great thickness of this port belt and to the preferred circular ports, it will be seen that each bar has in effect a steep taper from the middle of the port to the root of the bar where it engages the cold wall of the cylinder casting, whereat the surface in contact for each bar is many times the sectional area of the bar at its mid-point. It will be seen that by these means a greatly improved degree of conductivity from the mid-point of each port bar to the cooling medium is aflorded, and that the joints will not be subjected to opening up due to distortion of the parts. In this way the damage to the piston ring, characteristic of excessive port bar temperatures, is avoided.

In the prior art the port bars have been formed with longitudinal water passages for cooling in the case of the larger cylinders where the liner is not used. Where a liner is desired, as in the present invention, watercooled bars would involve a multiplicity of water joints between the liner and the cylinder which would be subject to leakage troubles. Hollow bars also take up more room, thus detracting from the available port area. One of the objects of the present invention is to achieve good cooling in a ported cylinder liner by simple means not subject to the foregoing disadvantages.

Due to the fact that the piston rings pass the ports, these must be subdivided into relatively short circumferential lengths in order toprevent the rings from expanding into the ports and striking the edges thereof. In the drawing, round ports have been shown, altho the invention is applicable to any desired shape of port.

In the drawing: 4

Fig. 1 is an axial sect-ion thru an engine cylinder embodying the construction of this invention, and

Fig. 2 is a plan section on the line 2-2 of Fig,

Referring first to Fig. 1. 1O designates the combustion chamber partof the cylinder and 12 the lower or base portion respectively pro vided withjackets 14 16 for a suitable cooling medium. These parts are enlarged to provide the port belt 18 provided with the outlet-port 20 to which suitable pine not shown) may be secured. The cylinder portions are secured together at the parting face 22 as by bolts 24 and are further. provided with'accurately machined annular faces 26 and 28 between which is tightly clamped the collar 30 formed integral with the sleeve or liner 32 which is closely fitted to the bores of the cylinder parts 10 and 12. A plurality of ports are formed thru the collar 30 which ports may be over-run by the piston 42. Suitable water passages are provided inthe jointing face 22 whereat packing rings 44 -vention is equally applicable to air cooled cylinders wherein the water jacket would be replaced by suitable cooling fins.

The operation of the device is as follows: 7 The faces 26 and 28 are maintained at low temperature by the coolingrncdiurn. The

axial thickness of the collar 30 is such that it is tightly pinched between these faces when the parts are assembled so that an intimate thermal contact is maintained whereby heat is abstracted from the collar 30 to the cooling medium, so that the temperature of the collar will be substantially the same as thatof the faces 26 and 28. It will be seen that the bars 48' defined between the ports l0 each subtend a large base of contact with the cooled faces 26 and 28 so that a very direct and efficient conductive path is afforded whereby the temperature gradient axially of the bars will be slight and the entire port zone of the sleeve will approximate the temperature of the cooled faces 26 and 28.

While I have described my invention in detail in its present preferred embodiment, it will be obvious to those skilled in the art after understanding my invention, that various changes and modifications may be made therein without departing from the spirit or scope thereof. I aim in the appended claims to cover all such modifications and changes.

What I claim is:

1. In an engine having ports overrun by a piston, the combination, of a cylinder liner having a collar containing the ports and upper and lower fluid cooled cylinder members fitted to said liner and having faces in intimate thermal contact with said collar.

2. In an engine, in combination, a cylinder comprising a combustion chamber portion and a base portion having faces defining an annular port belt therebetween, and a lining ing means, a liner engaged in said cylinder andhaving a collar engaging said annular face and ports thru said collar.

6. The combination with a cooled cylinder, of an improved cooling means for a ported c linder liner comprising an annular proj ection on the liner containing the ports and secured in intimate thermal contact with the cylinder. y b I 7. A cylinder comprising a combustion chamber art and a base part defining aport belt there etween having opposed and spaced annular faces, means for cooling said faces, a liner in said cylinder arts having a collar engaged between said aces and port openings formed, thru said collar. v F

8. A construction for cooling a ported cylinder comprising in combination, a cylinder having a boreand an annular face, means for cooling the walls of said bore and face, a liner engaged in said bore and having a collar engaging said face and ports formed thru said collar.

9. In an engine, a two-partcylinder, a liner for said cylinder, and an annular ported collar formed upon said liner and against which the respective cylinder parts are adapted to bear. I I

10. In an engine, in combination, a cylinder having cooling means and comprising two parts, each of said parts having a cooperating wall opposed to and spaced from the wall on the other partto provide an annular port belt therebetween, and a. liner for said cylinder parts having an annular ported collar clamped between said walls.

In testimony whereof I hereunto afix my signature.

ROLAND CHILTON.

sleeve for said portions having a ported annulus engaging said faces.

3. In an engine having a ported cylinder liner to be cooled, a port-containing-collar formed on the liner and comprising a shoulder of substantial area, and a cylinder having an annular face provided with cooling means and in intimate contact with said shoulder;

4. In a cylinder having a liner provided with a plurality of ports, means for cooling 7 the inter-port parts of the liner comprising,

in combination, a port-containing-collar extended from the liner to provide shoulders of substantial area adjacent tosaid ports, cylinder members having faces in intimate thermal contact with said shoulders, and means to cool said faces.

5. In an engine, in combination, a cylinder having an annular face provided with cool-

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